9902809640 has 16 divisors (see below), whose sum is σ = 22281321780. Its totient is φ = 3961123840.

The previous prime is 9902809589. The next prime is 9902809669. The reversal of 9902809640 is 469082099.

It can be written as a sum of positive squares in 2 ways, for example, as 9795852676 + 106956964 = 98974^2 + 10342^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123785081 + ... + 123785160.

Almost surely, 2^9902809640 is an apocalyptic number.

It is an amenable number.

9902809640 is an abundant number, since it is smaller than the sum of its proper divisors (12378512140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9902809640 is a wasteful number, since it uses less digits than its factorization.

9902809640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247570252 (or 247570248 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 9902809640 is about 99512.8616812922. The cubic root of 9902809640 is about 2147.4322791311.

The spelling of 9902809640 in words is "nine billion, nine hundred two million, eight hundred nine thousand, six hundred forty".